The present invention relates to an image displaying apparatus and method thereof, which displays drawings, such as maps, network diagrams, circuit diagrams, and design diagrams on a display such as a cathode ray tube (CRT) in a computer system.
Japanese Patent Application Laid-Open No. HEI 5-274441 discloses image displaying apparatus. In this application, nine sheets of bitmap are cut out from a kind of bitmap being a group of four sheets, and an image is formed by connecting the nine sheets of the bitmap. As another example of a conventional image displaying apparatus, Japanese Patent Application No. HEI 11-36792 discloses an image displaying apparatus and method thereof. In this application, a bitmap is formed by enlarging or reducing vector data.
FIG. 1 is a diagram showing a structure of this another conventional image displaying apparatus. As shown in FIG. 1, this conventional image displaying apparatus consists of an image information storing means 101, an image display deciding means 102, an image display forming means 103, a data display selecting means 104, and a display 105. And the image information storing means 101 includes a vector data storing means 111, and a vector data projecting means 112.
However, in the conventional technologies, in the method in which nine sheets of bitmap are cut out from a kind of bitmap being a group of plural sheets, and an image is formed by connecting the nine sheets of the bitmap, there is a problem that occurs frequently, i.e., a label positioned at the edge of the cut out bitmap is cut off from its middle part. And in the method in which the bitmap is formed by enlarging or reducing vector data, the label is also enlarged or reduced, consequently, it becomes difficult to read the characters.
It is therefore an object of the present invention to provide an image displaying apparatus and method thereof being an image displaying technology of vector data, in which enlarging or reducing the vector data is performed after separating label information (i.e., character information) included in the vector data, and determining a label display position.
According to a first aspect of the present invention for achieving the object mentioned above, at an image displaying apparatus which provides a vector data storing means for storing vector data used for enlarging or reducing a displayed image, an image display deciding means for determining an enlarging rate, display information, and a display region to be enlarged of said displayed image, and a display means for displaying said displayed processed image, the image displaying apparatus includes a label extracting means for extracting label information, being character information including in said vector data, from said vector data storing means, a label information storing means for storing label information that includes a group of a character string, display information, and a label display position, and a display label selecting means, to which said enlarging rate, said display information, and said display region to be enlarged of said displayed image are inputted from said image display deciding means, selects said label information in a group of said character string, said display information, and said label display position of said label information from said label information storing means, and determines a label display position, and outputs said label display position to said display means.
According to a second aspect of the present invention, in the first aspect, said display label selecting means searches for the display position of existing labels near the position of a candidate label display position where said label is desired to be displayed, and when no existing labels are displayed, determines said label display position as the candidate label position stored in said label information storing means,
when one label exists near the position of said candidate label display position, said label display position is determined at a position a designated distance from said candidate label display position and on a straight line that extends through said candidate label display position to the display position of the existing label,
when two labels exist near the position of said candidate label display position, said label display position is determined at a position a designated distance from said candidate label display position on a diagonal line of a parallelogram that extends through said candidate label display position, wherein said parallelogram has two sides that are two straight lines that extend from the display positions of said existing labels through said candidate label display position,
when three or more labels exist near the position of said candidate label display position, said label display position is determined at a position at the center of a circle through which the three existing labels nearest said candidate label display position pass,
when said candidate label display position extends out of a bitmap, said label display position is determined at a position a designated distance to the center of said bitmap so that said label is not cut at its middle part, and
when said label display position is moved such that said label display position overlaps with one of said existing labels, display of said label is canceled.
According to a third aspect of the present invention, an image displaying method of an image displaying apparatus which provides a vector data storing means for storing vector data used for enlarging or reducing a display image, an image display deciding means for deciding an enlarging rate, display information, and a display region to be enlarged of said display image, and a display means for displaying said processed displayed image, included the steps of: extracting label information being character information includes in said vector data from said vector data storing means, storing label information to a label information storing means that includes a group of a character string, display information, and a label display position of said label, inputting said enlarging rate, said display information, and said display region to be enlarged of said displayed image to a label display selecting means from said image display deciding means, inputting selectively said label information to be displayed in characters to said label display selecting means from said label information storing means, deciding a label display position of said display image, and displaying an image on said display means after a plurality of bitmap data formed from said vector data are connected, by attaching said label on said bitmap data.
According to a fourth aspect of the present invention, in the third aspect, said label display selecting means, includes the steps of: searching for the display position of existing labels near the position of a candidate label display position where said label is desired to be displayed, determining said label display position at said candidate label display position stored in said label information storing means, when there are no existing labels, and determines said label display position at a position a designated distance from said candidate label display position and on a straight line extended through said candidate label display position from the display position of an existing label, when there is one existing label near the position of said candidate label display position.
According to a fifth aspect of the present invention, in the third aspect, said label display selecting means includes the steps of: searching for the display position of existing labels near the position of a candidate label display position where said label is desired to be displayed, and determining said label display position at a position a designated distance from said candidate label display position on a diagonal line of a parallelogram that extends through said candidate label display position, wherein said parallelogram has two sides that are two straight lines that extend from the display positions of said existing labels through said candidate label display position, when there are two labels near the position of said candidate label display position.
According to a sixth aspect of the present invention, in the third aspect, said label display selecting means includes the steps of: searching for the display position of existing labels near the position of a candidate label display position where said label is desired to be displayed, and determining said label display position at a position at the center of a circle which through which the three existing labels nearest to said candidate label display position, when there are three or more existing labels near the position of said candidate label display position.
According to a seventh aspect of the present invention, in the third aspect, said label display selecting means includes provides the steps of: searching for the display position of existing labels near the position of a candidate label display position where said label is desired to be displayed, and determining said label display position at a position a designated distance to the center of a bitmap so that said label is not cut at its middle part when said candidate label display position extends out of a bitmap.
According to an eighth aspect of the present invention, in the third aspect, said label display selecting means does not display the image, when said label display position overlaps with one of said existing labels.
According to a ninth aspect of the present invention, there is provided a program storing medium of an image displaying method defined in aspects 3, 4, 5, 6, 7 and 8.